The present disclosure relates to systems and methods for cleaning wafers within integrated circuit (IC) device manufacturing processes and to systems and methods for polishing wafers.
Since the advent of the integrated circuit, the semiconductor industry has continuously sought to improve the density of integrated circuit components devices (transistors, diodes, resistors, capacitors, etc.). For the most part, improvements in density have come from reductions in feature size, allowing more components to be formed within a given area.
An essential tool for integrated circuit device manufacturing is photolithography. The minimum feature size that can be resolved by a photolithography system is referred to as the critical dimension (CD). The smaller the CD, the more difficult it becomes to keep an image in focus across a wafer surface. Contaminants and residues left on the back side of a wafer by prior processing can prevent the wafer from lying flat and cause defocus issues (focus spots). The back sides of wafers are often cleaned in preparation for photolithography to avoid focus spots.